whether it means that G .M.-or, for that matter, Shell or George Bush-tnùy be- lieves in the promise of hydrogen or just the opposite is difficult to sa)!. A car that runs on hydrogen does not, or at least need not, look in any way out of the ordinaI)T. For instance, on the outside the HydroGen 3 minivan \ -- --- , , t \,. .. bining hydrogen and oxygen across a pair of platinum electrodes, produced a small current. A few years later, he increased the electrical output by stringing together a series of such devices, but he seems never to have pursued the idea much further. "For my part, I must say that science to me generally ceases to become interesting as it becomes useful," Grove once observed. , - - ,,;-- "'k electrical, rather than mechanical, en- ergy-in this way; fuel-cell cars are simi- 1ar to battery-powered vehicles-and, using the same amount of energy; a fuel cell can propel a car nearly three times as far as an ordinary combustion engine. At the same time, cars represent a peculiar challenge: they require a great deal of power, are expected to travel long dis- u'u_",_ "'- ,,,, ", Automakers argue that stiffer regulations on emissions aren't needed, because new technology will solve all the problems. that G.M. brought to Capitol Hill is indistinguishable from an Opel Zafira, a vehicle popular in Europe, and, from the driver's perspective, operates in much the same fashion. But where a normal Zafira would have a gasoline tank the HydroGen 3 is equipped with a vacuum- insulated stainless-steel cannister built to keep liquid hydrogen supercooled at -253 0 C. And where a normal Zafira would have an engine a HydroGen 3 has a fuel cell, or really an assembly of fuel cells, called a stack. The basic idea behind the fuel cell- that hydrogen can be used to produce electricity-is generally credited to an En- glish polymath named William Grove, a friend of the pioneering physicist Michael Farada)!. Grove, by training a barrister- his most famous client was the so-called "Rugeley poisoner," who plied his victims with strychnine-was an enthusiastic ex- perimenter in his own right. Intrigued by studies of electrolysis, Grove reasoned that jf it was possible to break water down ð into its constitutive elements using an electric current, it might also be possible BJ to do the reverse. In 1839, in his London laboratory, he built a device that, by com- Not much practical use was made of Grove's invention until the nineteen- sixties, when General Electric developed fuel cells to provide electric power for the Gemini space flights. These days, fuel cells can be found on board the space shuttle and also in a variety of more mundane locations, including the base- ment of 4 Times Square. (The stack at 4 Times Square, where this magazine has its offices, provides fifteen per cent of the building's electricit)r.) Enthusiasts predict a variety of new applications for the tech- nology in the very near future. Engtneers at Intel, Motorola, and 3M, for example, are busy trying to produce a fuel cell small enough to fit inside a video camera or a mobile phone. At a recent trade sho Toshiba demonstrated a cell for laptops which it said could come on the market as early as next year. Assuming that the kinks can be worked out, such miniature fuel cells could last six times longer than conventional batteries. For a number of reasons-primary among them the inefficiency of the internal-combustion engine-automo- biles represent a particularly promising fuel-cell application. Fuel cells produce tances between refuellings, and are called on to last for ten years or more. Among the many obstacles to commercial pro- duction are cost (most fuel cells today are made with platinum), durability (fuel cells tend to degrade after a relatively short time), and fuel storage (hydrogen is so light that it is generally kept under ex- tremely high pressure or at a very low temperature). There are also concerns about safety; although fuel-cell advocates maintain that, owing to misunderstand- ings about the Hindenburg, the dangers of hydrogen have been greatly exagger- ated. (In a recent paper titled "Twenty Myths About Hydrogen," the physicist Amory Lovins argues that hydrogen is "at least as safe as natural gas or LPG" -liq- uefied petroleum gas-"and arguably is inherently safer than gasoline.") Finally; there is the problem of ob- taining hydrogen in the :first place. Al- though it is the most plentiful element in the universe, hydrogen on earth exists almost exclusively in combination with other substances. As a result, it must be extracted, a process that can itse]f re- quire a considerable amount of energ)T. (In the case of hydrogen obtaIned from THE NEW YORKER, AUGUST II, 2003 37